“The issues associated with the (Autonomic Logistics Information System) software update have been mitigated,” the Marine Corps said in a statement to CNN.

The jets are from Marine Fighter Attack Squadron 211 based at Air Station Yuma.

“Reliability of equipment and safety of our personnel are among the Marine Corps’ top priorities as we continue transitioning our legacy aircraft to the F-35 in the coming years,” the statement added.

The F-35’s Joint Program Office also issued a statement saying it and a team from the jet’s manufacturer, Lockheed Martin, have “identified the root cause and generated the software fix to resolve the issues identified by the USMC.”

The Marine Corps announced Thursday that it would “temporarily suspend” flight operations for 14 F-35B fighters due to the software issues.

Maj. Gen. Mark Wise, the commanding general of 3rd Marine Aircraft Wing, made the decision to suspend flight operations after “anomalies” were discovered in a recent Autonomic Logistics Information System software upgrade, the US Marine Corps said in a statement.

“There is nothing wrong with the performance or safety of the aircraft itself, but it is imperative that we ensure the ground-based ALIS system is working properly before flight operations continue,” Maj. Kurt Stahl, a spokesman for the 3rd Marine Aircraft Wing, told CNN in an email.

Sen. John McCain, chairman of the Senate Armed Services Committee and frequent critic of the F-35’s development challenges, said he was “concerned” about the suspension.

“I was concerned to learn that the Marine Corps has suspended F-35B operations at MCAS Yuma due to problems with the aircraft’s Autonomic Logistics Information System. I am in close communication with the Marine Corps and Joint Program Office as they work to identify the root cause of these issues and resolve them as quickly as possible,” McCain said in a statement.

News of the suspension comes less than a week after the US Air Force’s 56th Fighter Wing at Luke Air Force Base in Arizona similarly suspended all flights of its 55 F-35As. The F-35A is the Air Force’s variant of the stealth fighter.

The Air Force told CNN that the pause came after five pilots experienced hypoxia-like symptoms. The pilots all used their backup oxygen to land the planes safely.

The two suspensions represent a setback for the $400 billion F-35 program, a long-delayed and over-budget weapons system that’s become the Pentagon’s most expensive in history.

The Marine Corps F-35B, which is capable of vertical landing, was the first of the F-35 Joint Strike Fighter variants to be declared combat-ready in 2015, and has since been deployed overseas. The Air Force’s F-35A was declared combat ready last year. The Navy’s variant, the F-35C, is supposed to be combat operational next year.

President Donald Trump has taken a personal interest in the F-35 program, slamming the costs as “out of control” and then getting involved in the Pentagon’s contract negotiations with Lockheed Martin. He took credit for generating $700 million in savings in the $8.5 billion contract for the latest batch of F-35A fighters.